Abstract
Background In spite of recent improvements in the outcomes of preterm infants, sepsis remains to be an important cause of mortality and morbidity. Studies have noted the rise of Gram-negative infections as causes of sepsis in the preterm population.
Objectives We aim to describe the epidemiology, trends and microbial distribution of neonatal sepsis episodes among preterm infants born <32 weeks gestation over a 13-year period.
Methods This is a retrospective single-centre cohort study of culture-confirmed neonatal sepsis episodes, which is defined as the isolation of pathogenic organism from blood and/or cerebrospinal fluid cultures. We included newborns that were admitted to the Neonatal Intensive Care Unit (NICU) who were < 32 weeks birth gestation and birthweight of ≤1500 g. Neonatal sepsis episodes were stratified into early-onset sepsis (EOS) occurring at <72 hours of birth and late-onset sepsis (LOS) occurring >72 hours after birth up till discharge.
Results A total of 2019 preterm infants were included in the study. The characteristics of the cohort: 52.7% male, median birth gestational age 28 weeks, 19.9% small-for-gestational age, 89.9% received antenatal steroids, 85.5% had a central venous catheter. Over the study period, 263 infants had a total of 273 episodes of culture-confirmed sepsis –49 EOS and 224 LOS episodes. Incidence of sepsis in this cohort decreased from a high of 24.2% in 2006 to 7.4% in 2017. This was concordant with a decrease in LOS over the same period: 16.8%-21.6% from 2005–2006 to 4.9% in 2017. EOS incidence remained relatively stable, ranging from 0–4.4%. Gram negative bacteria were the predominant pathogen group isolated, accounting for 186/281 (66.2%) of all organisms– 40/49 (81.6%) of EOS and 146/224 (65.2%) of LOS episodes. E Coli [24/49 (49.0%)] and Klebsiella spp [39/224 (17.4%)] were the most common microbial causes of EOS and LOS episodes respectively. Coagulase negative staphylococcus (CONS) accounted for 36/224 (16.1%) of LOS. Fungal infections were predominantly due to Candida spp - 12.1% (27/224) of LOS. Of note, there were no fungal infections detected over the recent 5 years.
Conclusions The decrease in the overall incidence of neonatal sepsis among preterm infants <32 weeks in our centre over the 13-year study period, is due to a reduction in LOS. Gram-negative bacterial organisms are the predominant infecting organism in this population with E.Coli and Klebsiella spp being the most common causes of EOS and LOS.
